The Sunnah of the Prophet can be divided into three categories: What the Prophet (Sallallahu Alaihi wa Sallam) did?What the Prophet (Sallallahu Alaihi wa Sallam) said?What is the third category?

Praise be to Allah, the Lord of the World; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

As for the third form of the Sunnah, it is the Prophet's sanctions/ practices tacitly approved by the Prophet.
Allah knows best.